Series-parallel magnetic switch



Jan. 29, 1963 D. E. COLVILI;

SERIES-PARALLEL MAGNETIC SWITCH 5 Sheets-Sheet 1 FiELed March 14, 1960 mw m a k 3 8 V l/ v mm 3 N O 3. L \V- \N 0B OF WI, N0 N0 2 INVENTOR. Dona/a E. Co/w'l/ BY 0 I R W H/s A fforney Jan. 29, 1963 D. E. COLVILL SERIES-PARALLEL MAGNETIC SWITCH Filed March 14, 1960 3 Sheets-Sheet 2 INVENiOR.

DandldE. Co/w'l/ C! RI W His Alia/nay Jan. 29, 1963 D. E. COLVILL 3,076,075

SERIES-PARALLEL MAGNETIC swrrca Filed March 14, 1960 3 Sheets-Sheet 3 Fig. 5

c a R W H/s Attorney United States Patent 3,076,075 SERIES-PARALLEL MAGNETIC SWITCH Donald E. Colvill, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Mar. 14, 1960, Ser. No. 14,650 4 Claims. (Cl. 200-104) This invention relates to electromagnetic switches and more particularly to electromagnetic switches of the seriespa-rallel type that are useful in motor vehicle electrical systems wherein a pair of storage batteries are connected in series when energizing a starting motor and are connected in parallel when being charged by a generator.

One of the objects of this invention is to provide a series-parallel magnetic switch that is economical to manufacture and reliable in operation.

Another object of this invention is to provide an electric switch that is comprised of a plurality of assemblies that are held together by fasteners which also serve to conduct current between contacts of the assemblies.

Still another object of this invention is to provide a series-parallel magnetic switch for connecting a pair of batteries in series when energizing a starting motor and connecting them in parallel when being charged by a generator, the switch including a plurality of assemblies held together by fasteners which serve to carry battery charging current.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the-accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

FIGURE 1 is a sectional view of a series-parallel magnetic switch made in accordance with this invention with two of the terminals illustrated 90 out of their true position.

FIGURE 2 is a sectional view taken along line 2-2 of FIGURE 1 and showing the terminals in their true position.

I FIGURE 3 is a sectional view taken along line 3-3 of FIGURE 1 and showing the terminals in their true position.

FIGURE 4 is a view illustrating a portion of the seriesparallel magnetic switch illustrated in FIGURE 1.

FIGURE 5 is a schematic electrical circuit diagram of the connection of the series-parallel magnetic switch of this invention with a generator, starting motor, and a pair of storage batteries.

Referring now to the drawings and more particularly to FIGURE 1, the switch of this invention comprises a first cap assembly 10, a second cap assembly 12, a third cap assembly 14 and a coil winding assembly 16. The cap assembly includes a tubular housing member 18 formed of insulating material which carries a pair of electrical contacts 20 and 22. The contact 20 has a threaded portion 24 forming a terminal connection and the contact 22 likewise has a threaded portion 26 forming a terminal connection. The contacts 20 and 22 are formed integral with the studs 24 and 26 and these are embedded or molded into the tubular housing 18. In FIGURE 1, the contact 22 is shown displaced 90 from its true position in order to better illustrate the internal parts of the seriesparallel magnetic switch.

The cap assembly 12 includes a tubular housing member 28 formed of suitable electrical insulating material. The tubular member 28 has embedded therein a terminal 30 having a downwardly projecting portion 32. Fitted within the tubular housing 28 is a contact assembly which is generally designated by reference numeral 34 and which is illustrated in greater detail in FIGURES 2 and 3 of the drawings. This contact assembly includes an insulator board 36 carrying at one side thereof the strap connectors 38 and 40 which are secured to the insulator board 36 as by riveting. The opposite side of the insulator board 36 carries strap connectors 42 and 44 which are likewise secured to the insulator board 36 as by riveting. The strap connectors 42 and 44 carry electrical contacts 45 which cooperate with pivotally moveable contactors 46 and 48. The pivotally moveable contactors 46 and 48 are pivoted to support brackets 50' and 52 which are supported by the insulator board 36. The springs 54 and 56 serve to hold the contactors 46 and 48 normally in engagement with the contacts 45 carried by strap connectors 42 and 44. A conductor 58 connects the pivotally mounted contactor 48 with its hinge bracket 52 and a conductor 60 connects the pivotally mounted contactor 46 with its hinge bracket 50. The brackets 50 and 52 are connected respectively with connectors 38 and 40 by rivets passing through insulator board 36.

The cap assembly 14 includes a tubular housing member 62 formed of electrical insulating material and carrying contacts 64 and 66 which are embedded in the tubular member. The contact 66 has a threaded terminal portion 68 and the contact 64 likewise has a threaded terminal portion 70. It will be appreciated that in FIGURE 1 the contact 66 and terminal 68 are once more shown shifted 90 out of their true position, the true position of the terminal 68 being indicated in FIGURE 2. The tubular member 62 also carries terminal connectors 72 and 74, the terminal 72 being illustrated in detail in FIGURE 1.

The coil winding assembly 16 includes a case 76 containing a coil winding 78. Positioned within the coil winding 78 is a member 80 formed of magnetic material and an armature 82 which is likewise formed of magnetic material. The coil winding 78 and the members 80 and 82 are separated by a sleeve 84, and it is seen that a spring 86 is positioned between the fixed member 80 and the shiftable armature 82. One end of the coil winding 78 is conected with terminal 72 via a conductor 68 and the other end of the coil winding 78 is connected with terminal 74 by means of a conductor which is not shown.

The cap assemblies 12 and 14 are held together by a pair of fastener screws 90 and 92 which are illustrated best in FIGURE 4. It is seen that the fastener screw 90 is threaded into the contact 66 carried by the tubular insulator member 62 and that the head of the screw 90 is in electrical contact with the strap connector 44 through a washer. In a similar manner the screw 92 has a portion threaded into the contact 64 and has a head in electrical contact with the strap connector 42. It will be appreciated that the fasteners 90 and 92 not only serve to hold the cap assemblies 12 and 14 together but also serve to hold the contact assembly 34 fixed with respect to the tubular housing member 28. These screws serve still another function in that they electrically connect the strap connector 44 with the contact 66 and the strap connector 42 with the contact 64.

The fastener which is designated by reference numeral 94 has a portion threaded into the strap connector 40 and has a head portion in electrical contact with the contact 20. It will be appreciated that this fastener serves to hold the cap assemblies 10 and 12 together and also serves to electrically connect the strap connector 40 with the contact 20.

The strap connector 38 illustrated in FIGURES 1 and 2 is connected with the extension 32 of terminal 30 by a fastener 96 which is threaded into the extension 32 and which has a head portion in electrical contact with the strap connector 38.

The series-parallel magnetic switch of this invention has an end cap 98 whit-h is held in place by a plurality of through bolts 100, one of which is illustrated in FIG- URE 1. These through bolts 100 are threaded into the coil winding assembly 16 and thus serve to hold the coil winding assembly 16 and the end cap 98 in fixed relationship with the cap assemblies 10, 12 and 14. In building up the seriesparallel magnetic switch of this invention, the cap'assemblies may be first secured together by means of screws 90, 92 and 94 and then the end cap 98 and coil winding assembly 16 are assembled and held to the cap assemblies by the through bolts 100. The tubular insulator members 18 and 28 are formed with slots through which the through bolts 100 pass whereas the tubular insulator member 62 of cap assembly 14 is of suflicient internal diameter to not obstruct the passage of the through bolts 100. It thus is apparent that the through bolts 100 will prevent relative rotation between tubular members 18 and 28 but are not in contact with the tubular insulator member 62.

The armature 82 of the coil winding assembly 16 is connected with a shaft 102 which carries contactors 104' and 106 which are insulated from the shaft by stepped insulating washers 108, 109, 110 and 111. The insulators 110 and 111 are slidable on the shaft and are biased toward a snap ring 112 by a spring 114 which is positioned between stop 116 and the insulator member 111. It will be apparent that the contactor 106 at times will connect the contacts 20 and 22 when the shaft 102 is shifted rightwardly in FIGURES l and 4. In a similar fashion, the insulators 108 and 109 are slidable on the shaft 102 with the washer 108 being biased into engagement with a washer 118 that engages a large diameter portion of shaft 102 by means of a spring 120 positioned between stop 122 and the insulator member 109. The contactor 104 will at times engage the fixed contacts 64 and 66 to complete a circuit between them and this will occur when the shaft 102 is shifted rightwardly in FIG- URES l and 4. The springs 114 and 120 permit some movement of the shaft with respect to the contactors 104 and 106 when they engage the fixed contacts 64 and 66 and 20 and 22. The shaft 102 carries a member 124 having arms 125 which engage the pivotally mounted contactors 46 and 48. The member 124 engages a member 126 located within insulator board 36 and this member is prevented from movement in one direction by snap ring 127. The member 124 engages stop 122 as is apparent from FIGURE 1. It will be appreciated that when the shaft 102 is shifted rightwardly in FIGURES l and 4 by the armature 82 the contactors 46 and 48 vn'll be shifted out of engagement with the contacts carried by strap connectors 42 and 44.

Referring now to FIGURE 5, a schematic electrical circuit diagram is illustrated for the series-parallel magnetic switch of this invention. It is seen that the terminal 26 of the switch is connected with a starting motor 128 and that the opposite side of the starting motor is connected to ground. The terminal 24 of the switch is connected with a lead wire 130 which in turn is connected to the positive terminal of the storage battery 132. The negative terminal of the storage battery 132 is connected with terminal 68 via the lead Wire 134. The terminal 30 is connected to groundvia a lead wire 136.

The terminal '70 is connected to one side of a generator 135 by means of lead wire 138 the opposite side of the generator being connected to ground. The terminal 70 is also connected to the positive terminal of storage battery 140 via a lead wire 142, theopposite side of the storage battery being grounded as shown. A manually operable switch 144 is connected between terminal 70 and a lead wire 146 which is connected with terminal 72. The terminal 74 of the switch is connected to ground via the lead wire 148.

In the operation of the subject series-parallel switch when the manually operable switch 144 is in an open position, the coil winding 78 will not be energized and the contactors 104 and 106 Will be in their positions illustrated in FIGURE 1 with the pivotally mounted contactors 46 and 48 in engagement with the strap connectors 42 and 44. With this set of conditions, the generator will charge the batteries 132 and in a parallel connection. The battery 140 will be charged from a circuit that includes the lead wire 138, the terminal 70, and the lead wire 142. The battery 132 will be charged through a circuit that includes the lead wire 138, the terminal 70, the contact 64, the fastener screw 92,. the strap connector 42, the pivotally mounted contactor 46, the conductor 60, hinge bracket 50, rivets passing through insulator board 36, the strap connector 40, the conductor screw 94, through contact 20* and terminal 24, through lead wire 130, through the storage battery 132, through lead 134, through terminal 168 and contact 66, through fastener 90 to conductor strap 44, through pivotally mounted contactor 48, through conductor 58 to hinge bracket 52, through rivets passing through insulator board 36 to strap connector 38, through extension 32, through terminal 30 and through lead 136 to ground. It can be seen that this charging circuit for charging the battery 132 makes use of all the fastener members 90, 92 and 94 and also makes use of both pivotally mounted contactors 46 and 48. It will also be appreciated that the contactors 104 and 106 are not used during the time that the generator is supplying charging current to the parallel connected batteries 132 and 140.

When it is desired to energize the starting motor 128 with a voltage that is equal to the series connected voltages of batteries 1.32 and 140, the manually operable switch 144 is closed. The closure of the manually operable switch 144 completes a circuit for the coil winding 78 which may be traced from lead wire 142, through switch 144, through conductor 146 to terminal 72, through the solenoid winding 78 and then through terminal 74 and lead wire 148 to ground. The energization of relay coil 78 causes the armature 82 to be shifted rightwardly and causes the contactors 104 and 106 to respectively connect contacts 64 and 66 and contacts 20 and 22. Just before this time, the pivotally mounted contactors 46 and 48 are shifted out of engagement with the contacts carried by strap connectors 42 and 44.

The circuit for the starting motor may now be traced from battery 140 through lead wire 142, through terminal 70 and contact 64, through the contactor'104 to contactor 66 and terminal 68 through lead wire 134 through battery 132, through lead wire 130, through terminal 24 and contact 20, through contactor 106 to contact 22 and terminal 26, and then from terminal 26 to the starting motor 128. The starting motor will now be energized by the series connected battery 132 and 140 to cause cranking of an internal combustion engine. In a typical installation, the storage batteries 132 and 140 are 12 volt batteries so that the starting motor is energized with 24 volts whereas the generator has slightly greater than 12 volt output to charge the 12 volt battery 132 and 140* in parallel. It will be observed that during the time that the cranking motor 128 is being energized, none of the fasteners 90, 92 and 94 are in the circuit and neither the contactor 46 or 48 is in the circuit. The current supplied to the starting motor 128 in so far as switching elements is concerned is carried by the contacor-s 104 and 106 and their mating fixed contacts.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A series-parallel magnetic switch comprising, a plurality of housing members, electrically conductive fastener means securing said housing members together, first and second pairs of fixed contacts carried by said housing members, a solenoid having a shiftable armature, first and second contactors shiftable with said armature and engage screws able with said first and second pairs of fixed contacts, a pair of pivotally mounted contactors, a third pair of fixed contacts cooperable with said pivotally mounted contactors, and means electrically connecting said second pair of fixed contacts with said third pair of fixed contacts including said electrically conductive fastener means.

2. A series-parallel magnetic switch comprising, first, second and third housing members, said first housing member carrying a first pair of fixed contacts, a second pair of fixed contacts carried by said second housing member and a third pair of fixed contacts carried by said third housing member, electrically conductive fastener means securing said housing members together and electrically connecting certain of said fixed pairs of contacts together, said electrically conductive fastener means having one end thereof threaded into respective contacts a solenoid having a shiftable armature, and contact means shiftable' by said solenoid armature cooperating with said first, second and third pairs of fixed contacts.

3. A series-parallel magnetic switch comprising, first, second and third housing members, a solenoid assembly engaging one of said housing members, said solenoid assembly including a shiftable armature, a first pair of fixed contacts embedded in said first housing member, a contact assembly supported by said second housing member including a second pair of fixed contacts and a pair of pivotally mounted contactors, a third pair of fixed contacts embedded in said third housing member, a pair of contactors shiftable with said armature into engagement with said first and third pairs of fixed contacts, means carried by said armature for shifting said pivotally mounted contactors out of engagement with said second pair of fixed contacts, means securing said second and third housing members together including electrically conductive fastener means electrically connecting said second pair of fixed contacts with said third pair of fixed contacts, and another electrically conductive fastener member securing said first housing member to said second housing member and electrically connecting one of said first pair of fixed contacts with one of said pivotally mounted contactors.

4. A series-parallel magnetic switch for connecting a pair of storage batteries in series with a starting motor and for connecting said batteries in parallel with a generator comprising, first, second and third housing members formed of insulating material, a first pair of terminals providing fixed contacts supported by said first housing member, a contact assembly including a second pair of fixed contacts and a pair of pivotally mounted contactors supported by said second housing member, a third pair of fixed contacts carried by said third housing member, a solenoid including a shiftable armature, a pair of contactors shiftabie with said armature into engagement with said first and third pairs of fixed contacts, said armature causing shiftable movement of said pair of pivotally mounted contactors when it is shifted, first and second electrically conductive fasteners securing said second and third housing members together and electrically connecting said second and third pairs of fixed contacts, and a third electrically conductive fastener securing said first and second housing members together and electrically connecting one of said pivotally mounted contactors with one of said first pair of fixed contacts.

References titted in the file of this patent UNITED STATES PATENTS 2,591,336 Bordelon Apr. 1, 1952 2,725,488 Huelfed et al Nov. 29, 1955 2,895,057 Couthlin July 14, 1959 2,951,133 Davies et a1. Aug. 36, 1960 

1. A SERIES-PARALLEL MAGNETIC SWITCH COMPRISING, A PLURALITY OF HOUSING MEMBERS, ELECTRICALLY CONDUCTIVE FASTENER MEANS SECURING SAID HOUSING MEMBERS TOGETHER, FIRST AND SECOND PAIRS OF FIXED CONTACTS CARRIED BY SAID HOUSING MEMBERS, A SOLENOID HAVING A SHIFTABLE ARMATURE, FIRST AND SECOND CONTACTORS SHIFTABLE WITH SAID ARMATURE AND ENGAGEABLE WITH SAID FIRST AND SECOND PAIRS OF FIXED CONTACTS, A PAIR OF PIVOTALLY MOUNTED CONTACTORS, A THIRD PAIR OF FIXED 